Genuine Mazda Valve (Made in Germany)
ECC81 / 12AT7 Dual Triode
Top Ring Getter
BVA Marked
New in Original Boxes
Amplitrex AT1000 Tested
Up for sale is a strong pair (2 pieces) of authentic vintage Mazda ECC81 (12AT7) dual triode vacuum tubes, preserved in their original vintage Thorn blue boxes. Manufactured in Germany, these tubes feature a top ring getter structure, clean glass print with BVA markings, and legendary German production quality. Highly prized by audiophiles for their exceptional transparency, low noise, and rich dynamic performance.
As shown, both tubes have been precisely tested on an advanced Amplitrex AT1000 tube testing system operating in full fixed-bias mode. Plate current (Ip) and mutual conductance (Gm) measurements alongside percentage performance ratings relative to nominal factory specs are detailed in the table below.
| Serial No. |
Triode Section |
Plate Current (Ip) |
Transconductance (Gm) |
| Ref Spec |
Result |
% Ip |
Ref Spec |
Result |
% Gm |
| SR.NO. 370018 |
Triode 1 (T1) |
10.0 mA |
7.0 mA |
70% |
5500 µMhos |
5300 µMhos |
96% |
| Triode 2 (T2) |
10.0 mA |
7.8 mA |
78% |
5500 µMhos |
5420 µMhos |
99% |
| SR.NO. 370026 |
Triode 1 (T1) |
10.0 mA |
9.0 mA |
90% |
5500 µMhos |
5400 µMhos |
98% |
| Triode 2 (T2) |
10.0 mA |
8.2 mA |
82% |
5500 µMhos |
5160 µMhos |
94% |